If everything gets timely paid, over many, many years, or through a lump sum through some future refinancing, then the mortgage holder will issue and file a release/satisfaction for full payment. I have to believe Georgia law doesn't require any of the mortgagors to be alive, or have a successor in interest established through probate, in order for the release to be effectual. If obligations are not timely paid, it's the mortgage company that may (or may not in Georgia) be compelled to commence a probate in order to identify successor parties for serving notices of acceleration, foreclosure, etc. . . . One small snafu might arise at the end if you are issued an escrow refund and two names are on the check, but that can usually be accommodated.
As a co-signer or co-borrower, your mother's property interests were liabilities, not assets. But that has to do with the underlying promissory note. Her additional participation in the mortgage was really not needed if she had no property interest in the collateral real estate as an owner.
But if she also has an ownership interest in the real estate (which is when she would need to join in the mortgage in addition to the note), that's an entirely different matter, and while the mortgage release could still be handled without concerns for probate, any other succession of her other interests of real estate ownership would almost certainly require probate unless joint tenancy with rights of survivorship passed her interests.
Hope this helps.
GL
